Home automation or smart home[1] (also known as domotics or domotica) is the residential extension of building automation and involves the control and automation of lighting, heating (such as smart thermostats), ventilation, air conditioning (HVAC), and security, as well as home appliances such as washer/dryers, ovens or refrigerators/freezers that use WiFi for remote monitoring. Modern systems generally consist of switches and sensors connected to a central hub sometimes called a "gateway" from which the system is controlled with a user interface that is interacted either with a wall-mounted terminal, mobile phone software, tablet computer or a web interface, often but not always via internet cloud services.

While there are many competing vendors, there are very few world-wide accepted industry standards and the smart home space is heavily fragmented.[2] Popular communications protocol for products include X10, Ethernet, RS-485, 6LoWPAN, Bluetooth LE (BLE), ZigBee and Z-Wave, or other proprietary protocols all of which are incompatible with each other.[3] Manufacturers often prevent independent implementations by withholding documentation and by suing people.[4]

The home automation market was worth US$5.77 billion in 2015, predicted to have a market value over US$10 billion by the year 2020.[5]

In 1975, the first general purpose home automation network technology, X10, was developed. It is a communication protocol for electronic devices. It primarily uses electric power transmission wiring for signalling and control, where the signals involve brief radio frequency bursts of digital data, and remains the most widely available.[7] By 1978, X10 products included a 16 channel command console, a lamp module, and an appliance module. Soon after came the wall switch module and the first X10 timer.

By 2012, in the United States, according to ABI Research, 1.5 million home automation systems were installed.[8]

According to Li et. al. (2016) there are three generations of home automation:[9]

Appliance control and integration with the smart grid and a smart meter, taking advantage, for instance, of high solar panel output in the middle of the day to run washing machines.[11][12]

Security: a household security system integrated with a home automation system can provide additional services such as remote surveillance of security cameras over the Internet, or central locking of all perimeter doors and windows.[13]

A WiFi network connected to the internet can be vulnerable to hacking.

Technology is still in its infancy, and consumers could invest in a system that becomes abandonware. In 2014, Google bought the company selling the Revolv Hub home automation system, integrated it with Nest and in 2016 shut down the servers Revolv Hub depended on, rendering the hardware useless.[17]

Microsoft Research found in 2011, that home automation could involve high cost of ownership, inflexibility of interconnected devices, and poor manageability.[18]

Historically systems have been sold as complete systems where the consumer relies on one vendor for the entire system including the hardware, the communications protocol, the central hub, and the user interface. However, there are now open source software systems which can be used with proprietary hardware.[18]

There are a wide variety of technology platforms, or protocols, on which a smart home can be built. Each one is, essentially, its own language. Each language speaks to the various connected devices and instructs them to perform a function.

A family of X10-compatible lighting and home control products from SmartLabs Inc. that use both 915 MHz RF and powerline to transmit signals. All Insteon devices are repeaters of Insteon signals, which means the more devices installed in the home, the better the wireless network performs. Insteon devices accept and receive signals from X10 devices, but do not repeat them.

A remote control system for lamps and appliances from X10 Wireless Technology that uses the home's electrical system as the signaling network. The standard powerline system since it was developed in 1975 for many years, x10 transmitters and receivers are set to one of 256 low-voltage codes. The controller, which contains the switch and transmitter, is an external unit that plugs into any AC outlet, or it replaces the light switch on the wall. The receiver plugs into the AC outlet, and the lamp or appliance plugs into the receiver. When the switch is activated, it sends a signal into the electrical line that is picked up by the receiver, which turns on/off or dims the lights. Several lamps can be treated as one group by setting their receivers to the same code. RF is 310 MHz in North America and 433 MHz in Europe.

Transmits commands and status within a LAN. Some systems, such as the Squeezebox audio player are directly controlled through an Ethernet connection. Others require a computer to bridge the xPL messages to the equipment's hardware interface such as RS-232.

ZigBee PRO and ZigBee Remote Control (RF4CE), among other available ZigBee profiles, are based on the IEEE 802.15.4 protocol, which is an industry-standard wireless networking technology operating at 2.4 GHz targeting applications that require relatively infrequent data exchanges at low data-rates over a restricted area and within a 100 m range such as in a home or building. Additional radio frequencies used are 915 MHz (Americas and Australia) and 868 MHz (Europe).

Home automation devices amorphous computing nature is also a problem for security, since patches to bugs found in the core operating system often do not reach users of older and lower-price devices.[29][30] One set of researchers say that the failure of vendors to support older devices with patches and updates leaves more than 87% of active devices vulnerable.[31][32]